<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<link href="https://cdnjs.cloudflare.com/ajax/libs/video.js/7.3.0/video-js.min.css" rel="stylesheet">

<body>
  <!-- <video id="example_video_1" class="video-js vjs-default-skin" controls preload="none" width="640" height="264">
    <source src="http://ivi.bupt.edu.cn/hls/cctv1hd.m3u8">
    </video> -->
  <script src="https://cdnjs.cloudflare.com/ajax/libs/video.js/7.3.0/video.min.js"></script>
  <script>
    
// var player = videojs('example_video_1',{
//     muted: false,
//     controls: true, 
//     autoplay:true,     
//     height:600, 
//     width:800,
//     // loop : true,
//     // 更多配置.....
//   })
function add(a = 0,b = 0,c = 0){
  let num = 0
  num = a+b+c;
  console.log(num)
  return function(d = 0,e = 0){
    num = num + d+e;
    console.log(num)
    return function(f = 0){
      num = num + f;
      console.log(num)
    }
  }
}
// add(1);
// add(1)(2);
add(1)(2)(3)
// add(1)(2,3);
// add(1,2)(3);
// add(1,2,3)
  </script>
</body>
</html>